2026-07-30 カリフォルニア大学サンディエゴ校（UCSD）
Hydroxyapatite is the primary inorganic component of bones and hard tissues, and highly relevant in a variety of medical applications. The incorporation of dopants into the calcium sites of this material introduces atomic defects that endow it with unique luminescent properties for bioimaging applications.
＜関連情報＞
- https://today.ucsd.edu/story/uc-san-diego-researchers-use-sdscs-expanse-to-better-understand-bone-like-minerals
- https://www.sciencedirect.com/science/article/abs/pii/S0022459626000903
Eu3+ドープヒドロキシアパタイトにおける電荷補償、構造応答、およびドーパント分布：密度汎関数理論による研究 Charge compensation, structural response, and dopant distribution in Eu3+-doped hydroxyapatite: A density functional theory study
J. Arturo García-Cortés, Fabián Martínez-Pallares, Manuel Herrera, Olivia A. Graeve
Journal of Solid State Chemistry Available online 13 February 2026
DOI:https://doi.org/10.1016/j.jssc.2026.125894
Highlights
- Incorporation of rare-earth dopants into hydroxyapatite introduces atomic defects.
- Unique luminescent properties result from the presence of dopants.
- These properties are potentially useful in bioimaging applications.
- Substitution of Eu3+ for Ca2+ is charge compensated by the deprotonation of OH−.
- Variations in lattice parameters depend on the charge compensation mechanism.
Abstract
Hydroxyapatite (HAp) is the primary inorganic component of bones and hard tissues in mammals, and thus highly relevant in a variety of medical applications. The incorporation of dopants into HAp introduces atomic defects that endow it with unique luminescent properties, potentially useful for bioimaging. This study aims to deepen the understanding of the structure and energetics of europium-doped HAp through ab initio simulations at low dopant concentrations. Using density functional theory within the generalized gradient approximation, we conducted calculations on 352-atom supercells of both undoped and europium-doped HAp. We explored the behavior of trivalent europium (Eu3+) and its effect on the HAp crystal lattice, focusing on Eu/[Eu + Ca] atomic ratios up to 0.05. Our analysis of relative defect formation energies indicates that the substitution of Eu3+ for Ca2+ is charge compensated preferentially via the deprotonation of an OH− group, leading to a homogeneous spatial distribution of Eu3+ ions within the HAp structure. In contrast, when calcium vacancies are utilized as an alternative charge compensation mechanism, the defects tend to distribute irregularly. Our results also highlight a preference for Eu3+ substitution at Ca(II) sites. Moreover, structure optimizations prove that the variations in lattice parameters of Eu3+-doped HAp with respect to pure HAp also depend on the charge compensation mechanism. The computed data align well with various experimental observations.
